The user sometimes views the content by displaying the video data of the content on the display device, and outputting the audio data of the content from an audio output device. If the display device and the audio output device are directly connected with a bi-directionally communicable transmission path, the display device can receive the setting information of the audio output device and display a GUI for changing the setting of the audio output device based on the relevant setting information. As a result, the user can change the setting of the audio output device through the GUI displayed on the display device. Patent literature 1 describes a system for controlling the operation of the display device and the like through a network.